• Title/Summary/Keyword: modified method

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Applicability Comparison of Transmission Line Parameter Extraction Methods for Busbar Distribution Systems

  • Hasirci, Zeynep;Cavdar, Ismail Hakki;Ozturk, Mehmet
    • Journal of Electrical Engineering and Technology
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    • v.12 no.2
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    • pp.586-593
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    • 2017
  • Modeling busbar distribution system as a transmission line is an important subject of power line communication in the smart grid concept. This requires extraction of busbar RLGC parameters, accurately. In this study, a comparison is made between conventional and modified method for the aspect of optimum RLGC parameters extraction in the 1 MHz to 50 MHz frequency band. The usefulness of these methods is shown both in time and frequency-domain analysis. The frequency-domain analyzes show that the inherent power of modified method can eliminate the errors especially due to the discontinuities arise in conventional method. This makes the modeling approach of modified method more advantageous for the busbars due to its robustness against disturbances in the S-parameters measurements which cannot be eliminated with the calibration procedure. On the other hand, time-domain simulations show that the transmission line representation of the modified method is closer to physical reality by handling causality issues.

Effectiveness of the Modified Position of Scapular AP Projection (견갑골 전후방향 검사 시 변형된 자세의 유용성 평가)

  • Huh, Jae;Lee, Seung-Chul;Park, Jung-Hoon;Kim, Kwang-Soo;Lee, Kwan-Sup
    • Korean Journal of Digital Imaging in Medicine
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    • v.15 no.2
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    • pp.7-11
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    • 2013
  • Purpose: This study was to evaluate effectiveness of the modified position in scapular AP (anteriopo-sterior) projection. Materials and Methods: From June 2012 to July 2013, scapular AP projection was examined in 108 patients by use of conventional method and in 40 patients by use of modified method. We compared between conventional method and modified method following variables including sex, age, height, weight, and BMI. We measured and compared distance between lateral border of the scapular and the rib to confirm the separation of the scapular from the lung fields including the ribs. Results: The scapular AP projection was technically successful in all patients. There was no significant difference in patient characteristics including sex, age, height, weight, and BMI between conventional method and modified method. The mean distance between lateral border of the scapular and rib in conventional method and modified method was 15.09 mm and 26.33 mm, respectively. Modified method was significantly increased the distance between lateral border of the scapular and rib compared with conventional method (P < .01). Conclusion: The modified position in scapular AP projection was effective method to separate between the scapular and lung fields including the ribs compared with conventional position of scapular AP projection.

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Comparative Analysis of Three Different Cervical Lateral Mass Screw Fixation Techniques by Complications and Bicortical Purchase : Cadaveric Study

  • Baek, Jin-Wook;Park, Dong-Mook;Kim, Dae-Hyun
    • Journal of Korean Neurosurgical Society
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    • v.48 no.3
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    • pp.193-198
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    • 2010
  • Objective : The purpose of this study is to compare the incidence of possible complications of cervical lateral screw fixation and the achievements of bicortical purchase using the Roy-Camille, Magerl and the modified methods. Methods : Six fresh-frozen cervical spine segments were harvested. The Roy-Camille technique was applied to C3 and C4, and the Magerl technique was applied to C5, C6, and C7 of one side of each cadaver. The modified technique was applied to the other side of each cadaver. The nerve root injury, violation of the facet joint, vertebral artery injury, and the bicortication were examined at each screwing level. Results : No vertebral artery injury was observed in any of the three methods. One nerve root injury was observed in each cervical spine segment using the Roy-Camille method (8.3%), the Magerl method (5.6%), and the modified method (3.3%). Facet joint injuries were observed in two cervical spinal segments using the Roy-Camille method (16.7%) and three with the Magerl method (16.7%), while five facet joint violations occurred when using the modified method (16.7%). Bicortical purchases were achieved on ten cervical spinal segments with the Roy-Camille method (83.3%) and Magerl method (55.6%), while twenty bicortical purchases were achieved in the modified method (66.7%). Conclusion : The advantages of the modified method are that it is performed by using given anatomical structures and that the complication rate is as low as those of other known methods. This modified method can be performed easily and safely without fluoroscopic assistance for the treatment of many cervical diseases.

A Study on the Conventional Liquefaction Analysis and Application to Korean Liquefaction Hazard Zones (기존의 액상화 평가기법 밀 그 적용성에 관한 연구)

  • 박인준;신윤섭;최재순;김수일
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.431-438
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    • 1999
  • An assessment of liquefaction potential is made in principle by comparing the shear stress induced by earthquake to the liquefaction strength of the soil. In this study, a modified method based on Seed and Idriss theory is developed for evaluating liquefaction potential. The shear stress in the ground can be evaluated with seismic response analysis and the liquefaction strength of the soil can be investigated by using cyclic triaxial tests. The cyclic triaxial tests are conducted in two different conditions in order to investigate the factors affecting liquefaction strength such as cyclic shear stress amplitude and relative density. And performance of the modified method in practical examples is demonstrated by applying it to liquefaction analysis of artificial zones with dimensions and material properties similar to those in a typical field. From the result, the modified method for assessing liquefaction potential can successfully evaluate the safety factor under moderate magnitude(M=6.5) of earthquake.

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Determination and Application of 3-Methylhistidine Levels in Urine (뇨(尿)중 3-Methylhistidine 함량의 측정과 이용)

  • 정수현;서형주
    • The Korean Journal of Food And Nutrition
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    • v.9 no.2
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    • pp.213-216
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    • 1996
  • A modified method is given for the precolumn derivatization and subsequent high-pressure liquid chromatographic seperation of 3-methylhistidine from urine. The elution contained isocratic solution with acetonirile and 10 M sodium phosphate(pH 7.5) requires less than 7 min. The recoveries of 3-methylhlstidine from urine control were 95% to 106%. 3-Methylhistidine determinations were performed on urine samples from volunteers who were both male trained and non-trained physical undergraduates. As the result, urinary .3-methylhistidine content of volunteers increased significantly after weight training.

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De-epithelialized dermal flap for nipple reconstruction: A modified star flap

  • Lee, Su Hyun;Kim, Deok Woo;You, Hi Jin;Jung, Jae A;Hwang, Na Hyun;You, Jae Pil;Yoon, Eul Sik
    • Archives of Plastic Surgery
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    • v.46 no.4
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    • pp.324-329
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    • 2019
  • Background Multiple approaches for nipple reconstruction exist, and none is considered superior to all others. The star flap is one of the most popular methods for nipple reconstruction, but gradual height loss is a major concern. We present a new modification of the star flap that incorporates a de-epithelialized dermal flap, along with the associated surgical results. Methods We reviewed the medical records of patients who underwent nipple reconstruction using the modified star flap method. The design was different from the conventional star flap in that the lateral wings were changed into a trapezoidal shape and de-epithelialized dermal flaps were added. The patients were followed up at 2, 4, 6, and 12 months postoperatively, and nipple height was measured. The postoperative nipple height achieved using the modified method was compared with that obtained using the traditional method. Results From February 2013 to June 2017, 32 patients received surgery using the modified star flap, and 18 patients who underwent nipple reconstruction before 2013 comprised the conventional method group. All patients had undergone breast reconstruction with an abdominal tissue-based flap. The mean follow-up period was 14.4 months in the modified method group and 17.3 months in the conventional method group. The mean maintenance of projection at 12 months postoperatively was $56.28%{\pm}18.58%$ in the modified method group, and $44.23%{\pm}14.15%$ in the conventional method group. This difference was statistically significant (P<0.05). Conclusions The modified method using a de-epithelialized dermal flap provides reliable maintenance of projection in patients who have undergone abdominal tissue-based breast reconstruction.

A Study on Cost Estimate for Building Parts in the Schematic Design Phase -Focusing on Educational Research Facility- (부분별 코스트산정법을 활용한 계획설계 비용예측에 관한 연구 - 교육연구시설을 중심으로 -)

  • Kim, Yo-Han;Lee, Baek-Rae;Kim, Ju-Hyung;Kim, Jae-Jun
    • Journal of KIBIM
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    • v.1 no.1
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    • pp.18-25
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    • 2011
  • Construction cost estimation in the early phase provides the opportunity to make reasonable decisions related to the project. For estimating this cost, various methods have been developed. But several problems have been recognized like accuracy, relation beteewn design and cost etc. In this study, we developed the method of cost estimating for building parts. The modified method has defferent ratio of space functions to calculate cost more correctly. Also historical cost data is used in this modified method for architects to estimate cost conveniently. By this modified method, we expects architects should easily design buildings based on cost.

The Modified Method of Orthotropic Rigidities for Stiffened Plates with Open Ribs (개단면 리브를 갖는 보강판에 대한 직교이방성 강성의 보정 방법)

  • Chu, Seok Beom;Choi, Young
    • Journal of Korean Society of Steel Construction
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    • v.16 no.2
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    • pp.191-200
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    • 2004
  • In this paper, the modified method of orthotropic rigidities for stiffened plates with open ribs is proposed to solve the problem of the inaccurate results of the orthotropic plate analysis according to the dimensions of stiffened plates. In analyzing various types of stiffened plates with open ribs using the isotropic and orthotropic plate element, orthotropic plates are found to gave smaller maximum displacements compared to isotropic plates in a range that is smaller than the special rigidity ratio and reversely. Therefore, obtaining a more accurate solution of the orthotropic plate analysis requires modifying the orthotropic rigidities of stiffened plates according to the rigidity ratio. This study presents two modified methods using the displacement function and the displacement ratio. The application of the two methods improves the accuracy of the results of the orthotropic plate analysis, although the modified method using the displacement ratio is better than the method using the displacement function in terms of serviceability and safety. The comparison with the experimental example shows that the proposed modified method improves accuracy. Therefore, the orthotropic plate analysis of stiffened plates with open ribs can achieve more accurate results using the proposed method in this study.

A Modified Method for the Boundary Fitted Coordinate Systems to Analysis of Gas Bearings Considering Upstream In Extremely High Compressibility Number Region

  • Khan, Polina;Hwang, Pyung;Park, Sang-Shin
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • pp.105-106
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    • 2002
  • An expanded scheme of direct numerical solution method for solving the Reynolds' equation in the boundary fitted coordinate systems for the gas lubrication with ultra low clearance is presented. Skewed slider is calculated by this scheme and results are compared to the original direct numerical solution. The modified scheme has advantages in stability in high compressibility number region. At the lower A region the difference in results of original and modified method is several percents.

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Comparative Studies on Short Term Blood Culture Method for Bovine Chromosome Investigation (소의 염색체 검사를 위한 혈액배양방법의 비교연구)

  • Park, Moo Seo;Jang, In Ho
    • Korean Journal of Veterinary Research
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    • v.14 no.2
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    • pp.227-231
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    • 1974
  • The studies were carried on to set up a short term blood culture method which is essential for doing bovine cytogenetic investigation and to reduce the amount of the various reagents wish better results obtained with modified methods were compared with the results of Basrur's and Halnan's methods, and the following results were obtained. 1. The modified method, with lesser amount of reagents than other methods, produced better results and showed cleaner spreads. 2. Better spreads were obtained, in the modified method, by modifying the hypotonic treatment. 3. Reduction of the PHA to 1/10 comparison with the other methods showed no harmful effects.

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